An air-conditioning apparatus includes an outdoor unit, a heat medium relay unit, and an indoor unit. The outdoor unit is installed in an outdoor space, which is a space outside a building including an air-conditioned space. The heat medium relay unit is installed in the outdoor space, and includes a housing that accommodates an intermediate heat exchanger. The indoor unit includes a load heat exchanger configured to exchange heat between air and a heat medium. The housing is installed to the outer wall of the building.